// COLMAP - Structure-from-Motion and Multi-View Stereo.
// Copyright (C) 2016  Johannes L. Schoenberger <jsch at inf.ethz.ch>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#ifndef RVG_SRC_BASE_DATABASE_CACHE_H_
#define RVG_SRC_BASE_DATABASE_CACHE_H_

#include <unordered_map>
#include <unordered_set>
#include <vector>

#include <Eigen/Core>

#include "base/camera.h"
#include "base/camera_models.h"
#include "base/database.h"
#include "base/image.h"
#include "util/types.h"

namespace RVG
{

// A class that caches the contents of the database in memory, used to quickly
// create new reconstruction instances when multiple models are reconstructed.
class DatabaseCache
{
public:
    DatabaseCache();

    // Get number of objects.
    inline size_t NumCameras() const;
    inline size_t NumImages() const;

    // Get specific objects.
    inline class Camera& Camera(const camera_t camera_id);
    inline const class Camera& Camera(const camera_t camera_id) const;
    inline class Image& Image(const image_t image_id);
    inline const class Image& Image(const image_t image_id) const;

    // Get all objects.
    inline const std::unordered_map<camera_t, class Camera>& Cameras() const;
    inline const std::unordered_map<image_t, class Image>& Images() const;

    // Check whether specific object exists.
    inline bool ExistsCamera(const camera_t camera_id) const;
    inline bool ExistsImage(const image_t image_id) const;

    // Manually add data to cache.
    void AddCamera(const class Camera& camera);
    void AddImage(const class Image& image);

    // Load cameras, images, features, and matches from database.
    //
    // @param database              Source database from which to load data.
    // @param min_num_matches       Only load image pairs with a minimum number
    //                              of matches.
    // @param ignore_watermarks     Whether to ignore watermark image pairs.
    void Load(const Database& database, const size_t min_num_matches,
              const bool ignore_watermarks);

    std::unordered_map<camera_t, class Camera> cameras_;
    std::unordered_map<image_t, class Image> images_;
};

////////////////////////////////////////////////////////////////////////////////
// Implementation
////////////////////////////////////////////////////////////////////////////////

size_t DatabaseCache::NumCameras() const
{
    return cameras_.size();
}
size_t DatabaseCache::NumImages() const
{
    return images_.size();
}

class Camera& DatabaseCache::Camera(const camera_t camera_id)
{
    return cameras_.at(camera_id);
}

const class Camera& DatabaseCache::Camera(const camera_t camera_id) const
{
    return cameras_.at(camera_id);
}

class Image& DatabaseCache::Image(const image_t image_id)
{
    return images_.at(image_id);
}

const class Image& DatabaseCache::Image(const image_t image_id) const
{
    return images_.at(image_id);
}

const std::unordered_map<camera_t, class Camera>& DatabaseCache::Cameras()
    const
{
    return cameras_;
}

const std::unordered_map<image_t, class Image>& DatabaseCache::Images() const
{
    return images_;
}

bool DatabaseCache::ExistsCamera(const camera_t camera_id) const
{
    return cameras_.count(camera_id) > 0;
}

bool DatabaseCache::ExistsImage(const image_t image_id) const
{
    return images_.count(image_id) > 0;
}

}  // namespace RVG

#endif  // RVG_SRC_BASE_DATABASE_CACHE_H_
